Keyway broach and pilot



Aug. 11, 1936. T. SUNDELL KEYWAY BROACH AND PILOT Filed June 4, 1935 Theo. Smell INVENTOR av mymw ATTORN EY Patented Aug. 11,1936

UETE STAS I F F i 1 Claim.

The invention relates to a broach and pilot and especially to a keyway broach and pilot.

The primary object of the invention is the provision of a device of this character, wherein 5 the same is adaptable for use in a press, either hand operated, hydraulic or mechanically controlled so that in a single stroke of the broach a keyway can be formed in a hole provided in a piece of work.

Another object of the invention is the provision of a device of this character, wherein the pilot is of novel construction so that wear thereon will be reduced to a minimum and the broach will be guided in its stroke for the cutting of a keyway in a piece of work, the broach being readily sharpened and maintained in perfect working order.

A further object of the invention is the provision of a device of this character, which is simple in construction, thoroughly reliable and efficient in operation, possessing but few parts, strong, durable, readily and easily operated and inexpensive to manufacture and install.

With these and other objects in view, the invention consists in the features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawing, which discloses the preferred embodiment of the invention and pointed out in the claim hereunto appended.

In the accompanying drawing:

Figure l is a fragmentary elevation of a press of a conventional type showing the pilot and broach constructed in accordance with the invention fitted therewith, the broach being partly in section.

Figure 2 is a horizontal sectional view through the broach showing the pilot in plan.

Figure 3 is an elevation of the pilot.

Figure 4 is a vertical sectional view showing a slight modification of the pilot.

Similar reference characters indicate corresponding parts throughout the several views in the drawing.

Referring to the drawing in detail, A designates generally a portion of a press which may be either hand operated, hydraulically or mechanically controlled or otherwise and includes a bed or base l and a plunger II, respectively The plunger 5 l is operated in any desirable manner. Within the bed or base I0 is an opening I2 for accommodating a pilot which comprises a circular body l3 having the reduced portion l4 correspondingly shaped to the opening l2 in th bed or base l0 and the enlarged portion (5 which rises above the top face of the bed or case, these portions l4 and I5 being cut into to provide a vertical slot forming a guideway IS. The body I5 is made from tool steel and in the guideway l6 against the innermost wall thereof is 5 placed a wearing strip forming a track H, the strip being preferably made from steel, bronze or any friction resisting material and is held in place by fasteners l3.

Working against this strip H is the broach 10 19 which is preferably made from tool steel and is tapered in the direction of its cutting teeth 20, these teeth being of less width than the width of the broach l9 and are of a style to cut a keyway 2! in a piece of work 22, only a portion 15 thereof being shown.

The body l3 of the pilot has formed at the upper face thereof a vertically disposed throat extension 23, it being slotted at 2% correspondingly to the slot or way l6 and in this slot 24 is 20 extended the strip I! for the broach IS, the slot 24 next to the portion thereof opening into the way l6, confronted by a segmental shaped protector plate or guard 25 which prevents the breaking away of material ahead of 25 the broach at the slotted side thereof and this plate or guard 25 is made secure by fasteners 26.

In Figure 4 of the drawing there is shown a slight modification wherein the extension 27 of the pilot 28 is of outwardly tapered formation 30 while the upper face 29 of said pilot 28 is at an inclination so that the broach will cooperate with a piece of work-disposed at an inclination in the press.

By a single stroke of the broach 19 under the 35 influence of the plunger H a keyway can be cut in a piece of work and this being obvious from Figure 1 of the drawing.

The extension 21 of the pilot 28 is adaptable for tapered holes in the work.

The strip I1 is a compensator for wear or when the broach has been sharpened shims may be placed underneath of said strip and in event that too much wear has taken place in the keyway, this strip would have to be removed and 45 a new strip substituted.

It is thought that the construction and manner of operation of the device will be clearly understood and, therefore, a more extended explanation has been omitted.

What is claimed is:

A device of the character described comprising an externally shouldered circular body having a longitudinally disposed slot opening through one side thereof, a reduced extension on 55 said body and rising from the upper end thereof and having a slot forming a continuation of the first-named slot, a, shoulder formed externally on the extension and next to the body and cut away at the slot, a wear strip removably fitted within the slot at the bottom thereof and coextensive with the length of the same, a rod-like broach movable through the slot and engaging the wear strip and having cutting teeth of less width than said broach, a protective plate fitting the cut away portion of the external shoulder of said reduced extension, and a support having the body fitted therein with the latter resting 5 upon its external shoulder.

'I'HEODORE SUNDELL. 

